Triorganophosphonium halides



United States Patent 3,452,099 TRIORGANOPHOSPHONIUM HALIDES Martin Grayson, Norwalk, Patricia Tarpey Keough,

Ridgefield, and Michael McKay Rauhut, Norwalk, Conn., assignors to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Division of application Ser. No. 344,224, Feb. 12, 1964, now Patent No. 3,299,143, dated Jan. 17, 1967. Continuation of application Ser. No. 627,572, Jan. 12, 1967. Thisapplication Sept. 1, 1967, Ser. No.

Int. Cl. C07f 9/28, 9/04 US. 'Cl. 260-6065 8 Claims ABSTRACT OF THE DISCLOSURE This is a division of application Ser. No. 344,224, filed Feb. 12, 1964, now US. Patent No. 3,299,143, and a continuation of Ser. No. 627,572, filed Jan. 12, 1967, and now abandoned.

The present invention relates to organophosphorus compounds and to a method of preparing same. More particularly, the instant discovery concerns phosphonium salt derivatives of tertiary phosphines.

It has been found that tertiary phosphines generally will react with halo-substituted ethanol to produce the con'espondginly trialkyl-, tricycloalkyl-, or tri-aryl- 2-hydroxyethylphosphonium salts. In turn, these salts may be acylated using a lower alkanoic anhydride, lower alkanoic acid, or the like, to produce their corresponding trialkyl-, tricycloalkyl, or triaryl- Z-acetoxyethylphosphonium salts.

The following equations illustrate this general reaction:

GB 9 R R BfiB XCH GHzOH n a a romcngon-x Q 9 RR R P CHlCHaOH-X esteriiying agent 0 s9 (n-C4H )3PCHgCHnO JCH -B r The trialkyl-, tricycloalkyl-, and triaryl 2 acetoxyethylphosphonium salts prepared as above may, in turn, be converted to their corresponding vinylphosphonium salts according to the following general equation:

base 9 R R R PCHzCHgOY-X R R R PCH=CHTX in which R R R and X are the same as above.

The following is a typical embodiment of Equation C, above:

3,452,099 Patented June 24, 1969 More specifically, in generic Equations A, B and C, above, R R and R each represent alkyl C -C substituted alkyl C C cycloalkyl, and aryl; X represents halogen, such as bromo, chloro and iodo, and tetraphenyl borate; and Y in Equations B and C represents the residue of an acylating agent as shown in the specific embodiments, supra.

Typical tertiary phosphine reactants are the followmg:

trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, tripentylphosphine, trihexylphosphine, triheptylphosphine, trioctylphosphine, trinonylphosphine, tridecylphosphine, triundecylphosphine, tridodecylphosphine, tritridecylphosphine, tritetradecylphosphine, tripentadecylphosphine, trihexadecylphosphine, dodecyldiethylphosphine, dioctylpropylphosphine, diethylbutylphosphine, butylethylhexylphosphine, tri(2-methoxypentyl)phosphine, tris-Z-cyanoethylphosphine, diethyl-Z-ethoxyheptylphosphine, tricyclopropylphosphine, tricyclohexylphosphine, triphenylphosphine, diphenylnaphthylphosphine, trixylylphosphine, tritolylphosphine, tris(paraethoxyphenyl)phosphine, tris(para-chlorophenyl)phosphine, tris(2-chlorophenyl)phosphine, tris(3-bromophenyl)phosphine, and the like.

Typical esterifying agents follow: lower alkanoic anhydrides, such as acetic anhydride, propionic anhydride, butanoic anhydride; lower alkanoic acids, such as formic acid, acetic acid, propionic acid, butanoic acid; acylating (Cg-C13 alkanoyl) halides, such as acetyl chloride, propionyl bromide, butyryl iodide, octanoyl chloride, dodecanoyl bromide, stearyl chloride, hexanoyl bromide; isopropenyl acetate; aryl sulfonyl halides, such as para-toluenesulfonyl chloride, phenyl sulfonyl bromide, 2,4 dimethylphenylsulfonyl chloride; alkyl (lower) chloroformates, such as ethylchloroformate, butylchloroformate; alkyl (lower) carbonates, such as diethylcarbonate, dipropylcarbonate, dibutylcarbonate; ketene; dimethyl sulfate; nitrosyl chloride; and trimethyl phosphate.

In Equation C, above, typical suitable inorganic and organic bases are: alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, lithium hydroxide; alkali metal carbonates, such as sodium carbonate, potassium carbonate, lithium carbonate; alkaline earth metal hydroxides, such as magnesium hydroxide, barium hydroxide, calcium hydroxide; alkaline earth metal carbonates, such as magnesium carbonate, barium carbonate, calcium carbonate; activated alumina; and quaternary ammonium hydroxides, such as tetraalkyl (lower)ammoni1nn hydroxides, including tetramethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabenzylammonium hydroxide; and basic ion exchange resins.

The reaction in Equation A hereinabove is carried out at a temperature in the range of 30 C. to 250 C., preferably 60 C. to 180 C. The Equation B reaction, above, is best carried out at a temperature in the range of 5 C. to 150 C. As to Equation C, above, this reaction is generally carried out at a temperature in the range of 20 C. to 180 C., preferably 50 C. to 150 C.

Each of these three reactions may be carried out at atmospheric, sub-atmospheric or super-atmospheric pressure; preferably, however, reaction is carried out at atmospheric pressure. By the same token, the ratio of the reactants in each of Equations A, B and C is not critical, an excess of either reactant, in each equation, with respect to the other being suitable. In Equation B, however, an excess of about by weight of the acylating agent relative to the phosphonium salt reactant is preferred. Generally in Equations A and C stoichiometric amounts of the reactants are employed.

The reactions of Equation A, above, are best carried out in the presence of an inert organic solvent, i.e., a solvent which does not enter into or otherwise interfere with the reaction under the conditions contemplated herein. Typical solvents are dimethoxyethane, dioxane, ethylacetate, tetrahydrofuran, and the like. I

Typical area: polymeric quarternary ammonium salts, e.g., polymeric trimethylbenzyl ammonium chloride, etc.

The reactions of Equation B similarly are best carried out in the presence of an inert organic solvent of the type described for Equation A, as well as acetic acid, dimethylformamide, diglyme, and the like.

As to Equation C, typical suitable inert organic solvents in which the phosphonium salt is solvent, which solvents do not interfere or enter into reaction to any substantial degree, are dimethoxyethane, dioxane, dirnethylformamide, diglyme, acetonitrile, ethylacetate, tetrahydrofuran, and other like linear and cyclic ethers, acetate esters (lower alkyl) Alternatively, it has been found pursuant to the nistant discovery that the products of Equation A, above, may be converted directly to the products of Equation C, thusly, D

in the presence of any base given above for Equation C and at a temperature in the range of 100 C. to 250 C. As in Equation C, a solvent of the type given hereinabove for Equation C is suitable and herein contemplated. If desired, the reaction may be carried out in the presence of a dehydrating agent, such as a siliceous agent-including silica (e.g., silica gel), silica-alumina, and the like, in which other inert organic solvents are also suitable, e.g., aromatic hydrocarbons, such as toluene, benzene, xylene, cymene, and the like, methylene chloride, ethylene chloride, etc.

The products of Equations A, B, C and D above are useful as fire retardants in plastics, e.g., from 0.5 to 30 parts by weight of any one of above compounds when incorporated into 100 parts by weight of a thermoplastic polymer material, such as polyethylene, polypropylene, polystyrene, polyacrylate, polymethylmethacrylate, or the like, provides enhanced fire retardance to the polymer material upon exposure to an open flame.

While the following examples specify certain details as to certain embodiments of the present invention, it is not intended that these details impose unnecessary limitations upon the scope of the instant discovery, excepting of course that these limitations appear in the appended claims:

Example I.tributyl-2-hydroxyethylphosphonium tetraphenylborate Tributyl-Z-hydroxyethylphosphonium bromide, obtained from combining tributylphosphine and 2-bromoethanol in 1,2-dirnethoxyethane and refluxing under nitrogen, is dissolved in water and treated with excess 0.1 N

4 sodium tetraphenylboron. The resulting precipitate is fill; ered and recrystallized from ethanol to yield product tributyl-2-hydroxyethylphosphonium tetraphenylborate with melting point 124 C.l C.

Analysis of product-Found: C, 80.03; H, 9.00; P, 5.35. C H5 O requires: C, 80.55; H, 9.25; P, 5.47%.

As is evident from this example, the halide salts of Equation A may be converted, in situ or after recovery thereof, to the corresponding tetraphenylborate salts.

Example II.-tributyl-2-acetoxyethylphosphonium :bromide 1,2-dimethoxyethane (275 milliliters), freshly distilled from calcium hydride, 2-bromoethanol (133 grams, 1.06 moles), and tributylphosphine (204 grams, 1.01 moles) are combined under nitrogen and refluxed at 85 C. overnight with stirring. A heavy oil forms within an hour.

' Isopropenyl acetate (320 grams, 3.2 moles),and"48% HBr (3 drops) are slowly added to the reaction mixture which is then refluxed 18 hours. Volatile components are removed in vacuo at C. Product (372.5 grams; 99.9% yield) remains as a thick hygroscopic oil, which could be forced to crystalline by stirring in a benzene-petroleum ether (boiling point 30 C.60 C.) mixture. Crystalline tributyl-2-acetoxyethylphosphonium salt is obtained from part of the oily product by freeze drying a benzene solution of the oil.

Example III.-tributyl-2-acetoxyethylphosphonium tetraphenylborate Tributyl-Z-acetoxyethylphosphonium bromide oil (16.2 grams produced as in Example II, above) is dissolved in water and treated with sodium tetraphenylboron (15 grams) dissolved in water. A white precipitate appears which is filtered and recrystallized from ethanol containing enough acetonitrile to cause solution at the boiling point of the mixture. Tributyl-2-acetoxyethylphosphonium tetraphenylborate (16.7 grams) is obtained with melting point of 177 C.l79 C.

Analysis of product.-Found: C, 76.65; H, 8.83; P, 5.24. C H O BP requires: C, 78.93; H, 8.94; P, 5.10%.

Example IV.triphenyl-2-acetoxyethylphosphonium iodide 2-iod0ethyl acetate is prepared from the nucleophilic exchange reaction of sodium iodide and 2-chloroethylacetate in refluxing acetone under nitrogen (boiling point 86 C.90 C. at 33 milliliters mercury). Triphenylphosphine (7.35 grams) is reacted with 2-iodoethylacetate (24 grams) under nitrogen with stirring at 80 C. for 4.5 hours. The excess 2-iodoethylacetate is distilled off in vacuo. Crude, brown crystalline product (14.20 grams) is obtained by washing oily residue with ether. It is washed with ether, ethylacetate, and acetone and re crystallized from acetonitrile to give product (7.90 grams) with melting point 161 C.l63 C.

Analysis of product.-Found: C, 55.16; H, 4.80; I, 26.77; P, 6.45. C H O IP requires: C, 55.47; H, 4.66; I, 26.66; P, 6.51%.

Example IV represents still another embodiment'of the present invention wherein the product salts of Equausing any of the tertiary phosphine reactants contemplated here in and the corresponding tri-substituted-Z acetoxyethylphosphonium halide produced and recovered, according to the following equation II a runner +XOHgCIIzOCCH3 a mwrcmcrnor-r z wherein R R R X and Y have the meanings given hereinabove in Equations A and B.

Equation E is best carried out at a temperature in the range of 5 C. to 150 C., preferably at the reflux temperature of the solvent employed. Typical inert organic solvents contemplated for Equation E are acetone, lower alkanol (ethanol, butanol), plus the solvents listed hereinabove for Equation C. The reaction under Equation E, as shown in Example IV, supra, is best carried out under inert conditions, such as under nitrogen. Other 2-haloethyl acetate reactants contemplated herein are 2-bromoethyl acetate and 2-chloroethyl acetate.

Tables A, B, C, D and E, which follow, correspond to Equations A, B, C, D and E, respectively. The examples in Tables A and B are carried out essentially as in Examples I and II, respectively, supra, excepting of course as shown in Tables A and B. These examples in Table C are carried out essentially as in Example LX, infra, excepting of course as shown in Table C. Likewise, the products of Table D are recovered essentially as in Example LX, infra. The examples in Table E are carried out essentially as in Example IV, supra, excepting of course as shown in Table E.

Moles R R BR'P X Mimi liters 0t Elolvent- Temp. Solvent 0. Product CH, CH; CH; 1 Br D-CJI III-C4; 11-04; 1 CI n-mm n-QH, 11-011, 1 cl vm... n-cm. n-oJi; n-om. 1 I

IX.- 1-0.3. i-olm 1-0411. 1 c1 JUL... CzeHa QnHa CuHn 1 CT XIII-.- 03H Call] Can't 1 C1 xrv elm car. mm,- 1 01 XVI... 1 Br XVII- 1 Cl XVIII. 1 I

See footnotes'at end of table.

1:0 DME 1,500 70 2-hydrosyethyl trlmethylphom ghontum romide.

1:0 DME 2-hydroxyethy1 4 trlbutylphosplmntum chloride.

Z-hydroxyethyltributylphosphonium chloride,

2-hydroxyethyltailbthtylphosox um iodide.

1. 2 Dloxane. 1, 101

1. 2 Dloxahe- '2, 000 101 D. 9 Z-hydroxyethyh trilsobutylphcs honium chlo do.

.khydroxyethyk trioetylphos--- phonimn chloride.

2-hydroxyeth 1- trldodecyly phosphonium chlortde.

Eth l-im- 1, am 5 so 1.1 DME 1,106" ea 1.; DME

1.3 THE Z-hydroxyethyltrthexadecyb. phosphonlum chloride.

z-hydrox eth'yI' trtothy phosphonium chloride.-

z-hydroxyethyle butylethylhexylphosphonlum chloride.

1.,0 Dloxanm h. 200.

1. l Ethyl Acetate.

1, 2 Dlomne. Z-hydroxyethyl'dll ethyl-2-ethqxyethylphos-' phonium chloride.

2-hydroxyeth'yltrtcyclohexylghosphonium,

romtde.

1.3 DME 0.9 ME.. 12,0) 80 2-hydroxyethyltrlcyclopentylphosphonlum chloride.-

1.1 Dioxenm... Y XYMhY fltphenylnaphthylphoaphontum iodide.

TABLE A.-Oontinued Moles Moles Milli- Temp. Ex. No. R R R R R R P X XCHgCHzOH Solvent liters of 0. Product Solvent 1 I i. Dioxene a, 000 101,. 2-hydroxyethyl- XIX. triphenylphosphonlum iodide.

' 1 Ci 1.2 Ethyl 1 000 05 2-hyrlroxyclhyl- Aegean, trl(pnre-chlm-0-,

plgen Upheap on um 61 C1 C1 chloride.

Cl 1.8 DME....... 1 700 83 i-llydroxyethyl- 1 trl (para-tolybpliosphonlum C c CH chloride.

1 DME-dlmethoxyethane. l TBF-tetmhydroiuren.

TABLE 13 Q a Q9 9 R R R POEGCILOH- A IURRPCH CHgOY-X Example Product Moles Solvent Temp.

N o. of Exam- Moles e A A Milllllters 0. Product P N0. R l'CH CH OH-X '(mL) 1. 0 Isopropenyl Acetate. 3. 2 DME, 800 ml 83 2-ecetoxyethyltrimethyl phosphonium bromide. 1. 0 Dlmethyl Sulfate. 3. 8 Dloxane, 300 00 2-methylsullatoethyltributyl phosml. phonium chloride. 0. 8 Acetic Anhydride 1. 0 Aescotolc alcid, 120 2-etlwleltoiiryethyltributyl phosplionium m c or e. 0. 9 Ni troeyl Chloride- 1. 1 Diglyme 120 2-riiitariraethyltributyl 'phosphonium o e. XXVI IX 1.0 Aoetyl Chloride 1. 2 DME, 500 ml Z-ecetoxyethyltriisobutjwlphosphonium chloride XXVII XI 1. 0 p-Toluenesulionyl 1. 0 'DME, 200 ml 2-(p-toluencsulfonyloxy)ethyltrichloride. p dodecyl hosphonium chloride. XXVIII.-.. XIII-..- 1. 0 Trimethyi Phosphate 1. 1 AceticAcid, 2-dimethy phosphetoethyltriethyl 500 m1. phosphonium chloride. XXIX XII...-. 1. 0 Propionic Acid 2. 4 DMF, 300 ml 10 2-propionyloxyethyltrlhexadecyihosphonium ehio e. XXX XIV.-.. 1. 0 Butanoic Anhydride 1. 0 DMF, 1,000 .30 2- utyryloxycthylbutylethylhexylml. phosphonium chloride. XXX! XV 0.8 Acetic Acid............ 4.0 None 118 2-ecetox ethyldiethyl-wethoxyethylphosp onium chloride. XXXH XVI-... 0. 9 Acetyl Chloride 1. 0 DME, 200 ml 65 2-acretot;yetlfi ltriogelohexylphosp on um rom e. XXXXII XVII.-- 1. 0 Hexenoyl Chloride.... 1. 9- Dioxane, 160 26 2-hexanoyloxyethyltrieyclopentylml. phosphonium chior e. XXXIV..... XIX.-.. 1.0 Acetic Anhydride....- 6. 0 None....- z-xitocgtigxyethyltriphenyl phnsphonium.

e. XXXV XV III" 1. 1 Stearyi Chloride... 8. 3 DME, 700 ml.. 50 2-steatyloxyethyldiphcnylnephthylphosphonium iodide. XXXVI. XX..-.- 1. 0 Dodec'anoyl 4. 0 DMF, 1,000 40' 2-dodecenoyloxyethyltri(pare-chlorm Bromide. ml. hcnyDphosphonium chloride. XXXVII. XXL..- 1. 0 Phenylsulionyl 1. 0 Dioxane, 65 2- plienylsulfonyioxy)ethyltri-(para Bromide. 600 ml. tolyl)phos honium chloride. XXXVIII- V 1. 0 Ethylchloroiormate... 2. 0 Diglyme, 40 2-(cthoxycar onyloxy)ethyltrimethyl 300 mi.v hosphonium bromide. XXXIX..... VII"-.. 0.9 Dipropyl carbonate..- 3.0 DME, 250 mi. 100 2- propoxyearbonyloxy)etliylp I trlbutylphosphonium chloride; XL VII. 1. 0 Ketene 1. 0 THE, 500 mL. 7 5 z-efiltcggethyitributyl phosphonium.

. c o e.=

DMF=dimethyliormamide.

By finely-divided particulates in Table D is intended 28 to 200 mesh. Larger or smaller particulates are likewise within the purview of the instant discovery.

Example LX.Tributylvinylphosphonium bromide Tributyl-2 acetoxyethylphosphonium bromide (23.7 millimoles) is dissolved in 1,2-dimethoxyethane (25 milliliters) and sodium carbonate (5.0 grams, 47 millimoles) is added. The mixture is stirred at reflux under nitrogen for 8 hours. The solid is filtered off and Washed with hot 1,2-dimethoxyethane. The combined filtrates are evaporated to leave a semi-solid residue. Recrystallization from ethyl acetate yields product tributylvinylphosphonimelitng point 148 C.-150 C.). Further recrystallization from ethylacetate-acetonitrile raises the melting point to 151.5 C. to 152.5 C.

Pursuant to the present discovery, the products of Tables B, hereinabove, and C, D and B, may be converted to their corresponding sulfur-containing derivatives by reaction with sulfhydryl (e.g., an alkyl mercaptan, an alkane dithiol, a benzenethiol, a dialkylphosphorodithioate, an 0,0-dialkylphosphorodithiolate, and the like) at a temperature in the range 20 C. to 200 C. Table F. G. H which follows illustrates this reaction, the examples in said table being carried out essentially as in Example LXXVI, infra, excepting of course as specified in the urn bromide (3.3 grams, 10.7 millimoles, 45% yield with 75 Table F, G, and H.

15 Example LXXVI Potassium 0,0-diethylphosphorodithiolate (13.0 grams, 0.06 mole) is dissolved in 50 milliliters of acetone and added dropwise to a stirred solution of tributylvinylphosphonium bromide (15.4 grams, 0.05 mole) in 50 milliliters of acetone. After standing overnight at room temperature, the mixture is filtered to remove precipitated potassium bromide and the acetone filtrate is treated with milliliters of 10% hydrobromic acid. Upon treating the resulting mixture with diethyl ether the product phosphonium salt is obtained in nearly quantitative yield as a viscous syrup.

Obviously, from Table F, G, H, the symbols R R R Y and X have the meanings given hereinabove in corresponding Equations A, B, C, D and E. The remaining symbols in Equations F, G and H of Table F, G, H have the following meanings:

As is evident from Table F, G, H, above, the reactions contemplated therein using 2-acetoxyethylphosphonium salts as reactants are carried out in the presence of a base of the type illustrated hereinabove for Equation C. By the same token, the vinylphosphonium salt reactants of Equations F, G and H, respectively, of Table F, G, H may be reacted as shown in said table using or omitting a base. Furthermore, the solvents of Equation C, supra, are contemplated for the reactions of Equations F, G and H, as well as atmospheric, sub-atmospheric and superatmospheric conditions. Similarly, an excess of either reactant with respect to the other is contemplated, although stoichiometric amounts are generally employed. It will be noted from Table F, G, H (cf. particularly Example LXXI) that tertiary alkyl (lower) amines are likewise contemplated as bases. The amount of base used in the Examples of Table F, G, H is 1 percent, based upon the total weight of reactants 1 and 2. Generally, from about .01 percent to about 10 percent ma be used.

The products of Equations F, G, H are useful as fire retardants in plastics in the same manner described hereinabove for the products Equations A, B, C and D.

Clearly, the instant discovery encompasses numerous modifications within the skill of the art. Consequently, while the present invention has been described in detail with respect to specific embodiments thereof, it is not intended that these details be construed as limitations upon the scope of the invention, except insofar as they appear in the appended claims.

We claim:

The compound of the formula:

wherein R R and R each represent a member selected from the group consisting of alkyl C C Substituted alkyl C -C cycloalkyl and aryl;

X represents halogen;

R represents a member selected from the group consisting of alkyl having from 1 to 12 carbon atoms, alkylene having from 1 to 12 carbon atoms, benzyl, benzene, toluene, xylene, and 2-naphthylene;

n is an integer of from 1 to 2.

The compound according to claim 1:

cmsomemr c.1113) (clue-(021101 20 The compound according to claim 1:

0119 1 omomsortfinr The compound according to claim 1:

1aHa1)aPCHz 2S emwnmcml ol The compound according to claim 1:

IX '3) omom s om ]ecre The compound according to claim 1:

UPCHzCHzSOD e e The compound according to claim 1:

. The compound according to claim 1:

7/1967 Grayson et al 260606.5

TOBIAS E. LEVOW, Primary Examiner.

W. F. W. BELLAMY, Assistant Examiner.

US. Cl. X.R.

o1 Ha j References Cited UNITED STATES PATENTS 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,452 ,099 June 24, 1969 Martin Grayson et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 66, "in which R R R and X are the same as above." should read in which R R R Y and X are the same as above Column 3, line 43, that portion of the equation reading 9 e R R R PCH cH 0H-x+ should read 9 e R R R PCH cH 0H-X Column 4, line 24, "crystalline" should read crystallize Column 7, line 63, beginning with "By" cancel all to and including "and H." in line 75, column 8, and insert the same after TABLE E in columns 9 and 10. Column 8, line 66, "Tables B, hereinabove, and C, D and B, may be converted" should read Tables B, C, D and E, hereinabove, may be converted line 75, "Table F, G, and H." should read Table: Column 16, line 18, "[(C H (C H )CP(C H )H CH SCH should read [(C H (C H (C H )PCH CH SCH lines 44 to 48, that portion of the formula reading CH3 H3 should read (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

